Spark-plug.



M. G. BUNNELL.

SPARK PLUG.

APPLlCATlOH FILED APR. 4. I9".

Patented July 30, 1918.

a W v MORTON G. BUNNELL, OF CHAMPAIGN, ILLINOIS.

SPARK-PLUG.

Specification 01 Letters Patent.

Patented July 30, 1918.

Application filed April 4, 1917- Serial No. 159,650.

To all whom it may concern.

Be it known that I, Mon'ron G. linzvivnnn, a citizen of the United States of America, and resident of Champaign, Champaign county, Illinois, have invented a certain new and useful lmprovei'nent in Spark-Plugs, of which the following is a specification.

My invention relates to spark plugs of that kind in which means are provided for readily removing the insulator from the socket without the use of tools.

It will be seen that this is an improvementon the spark plug disclosed in my prior application, No. 77,573.

Objects of my invention, as herein shown and described, are to provide an improved construction and arrangement whereby, in a spark plug of this kind, the metal jacket of the insulator cannot rot-ate in the socket which is screwed into the engine cylinder; to provide an improved construction whereby, in a spark plug of this construction. the inner end of the metal jacket will be provided with a resilient cushion, thus making it practical to use certain devices for forcing the insulator and its jacket tightly into the socket. and at the same time insuring a gastight joint where the inner end of the jacket is seated against the shoulder inside of the socket; and to provide an llIl )roved construction whereby, in the use 0 certain devices for forcing the insulator and its jacket tightly into the socket, the said devices will be adapted to firmly lock the different parts against displacement thus preventing the insulator and its jacket from being forced out of the socket by the pressure in the en ine.

To these and other useful ends, my inven- H in matters hereinafter set forth and emnned, d

In the accompanying drawings Figure 1 is a side elevation of a spark I plug embodying the principles of my invention.

Fig. 2 is a side elevation of the socket or bushing which is screwed into the engine cylinder.

Fig. 3 is a side elevation of the insulator and its jacket, and the pivoted bail or looking, device, showing the same withdrawn from the socket.

Fig. 4- is a vertical section of said sparkplug, showing the insulator in side elevation,

but showing the insulator jacket and the socket in section.

F g. 5 is a plan of the socket shown in Fig. 2,

Fig. 6 is a plan of the parts shown in Fig. 3.

Fig. 7 is a perspective of the split beveled steel ring.

Fig. 8 is an enlarged detail sectional view of one side of the ring shown in Fig. 7, showing the adjacent portions of the structure, and illustrating the manner in which said ring is contracted when the insulator and its jacket are forced into the socketmember by the locking device.

As thus illustrated, my invehtion c0mprises a metal bushing or socket piece A provided at its smaller end with a threaded portion 0 to screw into the cylinder of the engine. Internally, the socket A is provided with an upper shoulder 1 and a lower shoul der 2, formed by reductions in the diameter of the bore of the socket. The insulator B is oi any suitable material, and is provided with the usual electrodes 6 for producing the. spark at the other end of the plug. A metal jacket G surrounds the upper portion of said insulator. the lower end of said jacket being beveled at c, and a washer 3 of soft material and a steel ring D being interposed between the shoulder l and the bevel (7. thus forming a tight joint. The ring D, it will be seen, is beveled at d to en gage the bevel c, and is split at 4, whereby this rin' will contract as the jacket (1 is forced (ownward, and when the r ng 3 of soft material is compressed, thus providing a resilient cushion for the inner end of said jacket. The outer end of the insulator B is provided with a screw terminal 5, and a washer ti of insulating material is slipped over said screw and held in place by the nuts 7 nd 8 by which the electrical connection is made to the plug. The insulator B is provided with a shoulder 9 upon which the ring 3 is supported, and when the nuts 7 and 8 are screwed down against the. washer 6. which latter bears against the outer end of the jacket C, the inner end of the latter is forced against the ring \D, with the result that the ring 3 is forcedl against the shoulder 9, so that devices a e provided at the inner and outer ends of the jacket to removably hold the jacket in place on the insulator, whereby the insulator and its jacket can be removed as a unit from the socket. The ring D, of course, is removable from the outer end of the insulator, as the washer 6 is removed.

To hold the insulator and its jacket withinthe socket, the latter is provided.externally" licar against the upper sides of the rollers e to force the insulator and its jacket out of the socket, when the bail is thrown over to the position shown in Fig. 3, and is also provided with cams 11 which pass below and engage the under sides of the rollers c when the bail is thrown into the position shown in Fig. 1, thereby to force the insulator and its jacket down into the socket. The hub portions of the bail are also provided with depr share 12 whic '1 finally engage the undo! ides of said rollers c to allow the insulator and its jacket C to move slightly outn aid in the socket. and to lock the bail in tluposition shown in Fig. 1, thus preventing unlocking of the plug during the operation of the engine. \Vhen the dcpressinus l2 reach the rollers c, the jacket C is given said out ward movement by the action of the ring D, which latter by its resilient action, after being slightly compressed by the engagement of the cams 11 with the un der sides of the rollers c, expands suite ciently to produce this slight outward move ment of the jacket C when the bail f reaches its final position. The cams ll exert a power ful pressure on the under sides of the rollers c, and with such a locking, device it is not desirable to have the inner end of lli'e jackct or sleeve C encounter an ui'lyielding shoulder or seat in the plug-structure, as the cams 11 do not yield, and in order to bring the bail into locking position, with the insulator and its jacket firmly in the socket, there must be a slight yielding action somewhere, and this is taken care of by the resilient ring D which contracts during the action of sai cams and then immediately expands to force the jacket C slightly outwardand keep the rollers c firmly seated in the depressions 12 on the hub portions of the bail.

Furthermore, it will be seen that. the socket A is provided at its outer end with notches G at each side thereof, and that these notches receive the inner portions 13 which are rigid with the jacket C, and to which the pivots F, are suitably secured. When the portions 13 are in the notches G,

the jacket C cannot rotate in the socket A,

and the removable elements of the spark plug structure will always be brought into aui oosition, when inserted in the socket, in. la pivots F will be directly above the rollers e, so that the cams 11 will simultaneously engage these rollers when the bail is swung over into locking position. This prevents turning or twisting of the ackct in its socket, and insures the proper action of the locking device when the insulator and socket are to be forced down in the socket and locked (herein.

It will be seen, therefore, that the washer and ring 3 and D and the washer 6 serve as devices f r removably holding the sleeve C on the insulator B, the shoulder 9 cooperating, of course, with the washer 3 and the ring D to form one of said devices. In other words, these devices hold said sleeve against endwise displacement on the insulator, but inasmuch as one of the devices (the washer 6) is removable, it follows that these devices as a whole are of such cl'taracter that the sleeve or jacket can be readily removed from the insulator. With the construction shown and described, the said sleeve or jacket G, which may be of steel, forms a bottomless receptacle for the insu' lator. said receptacle having the bail f pivoted thereon to form a handle thcrcthr, so that the bail not only forms a lever by which to operate the cam devices for forcing the insulator and jacket intoand out of the socket, but serve also as a handle by which to lift said jacket and inst lator out of the socket-member A when such is necessary or desirable. The shoulder 2 will serve to limit the downward movement of the insulator in the socket-member, and a slight space can be left above this shoulder, below the shoulder 14 on the insulator, to nermit the dmvnward movement of the insulator when the cams l1 engage the lower sides of the rollers e, or this space can be occupied b a soft washer similar to the washer 3, t us further insuring against leakage. These washers can be made of any suitable material, such as thin copper and asbestos, and need not have any sprin 'or resilient action, inasmuch as the resl li ent effect is provided by the steel ring D, which latter is very strong and springy, and which serves by its expansion to immediately lift the insulator and its jacket, to a slight extent, as soon as the bail is thrown into the position shown in Fig. 1, so that the rollers e rest in the depressions 12 in the cams on the hiibs of the bail. The force by which the ring D is contracted is not communicated through the insulator, but directly from the jacket, so that there is no danger of breaking the insulator.

Of course, when the insulator B has been forced down as far as possible, so that the shoulder 14 bears hard against the shoulder 2, any further action of the cams 11 on the rollers 6 will then cause the sleeve or jacket C to slide downward u on the insulator, and it is at this time (at t e same time that the washer 3 is compressed on the shoulder 1) that the cmitraction of the spring ring I) takes place to permit the further downward movement of the jacket 0, thereby to prevent breakage. Thus the ring I) and the washer 3 form a sort of stalling box or gland for the cylindric upper portion of the insulator B, which latter may be of porcelain or other suitable material. thereby to not only prevent leakage while the engine is in operation, but also to prevent breakage when the insulator and its jacket are inserted and locked in position. \Vhen the washer (i is screwed down upon the upper end of the jacket C, the adjustment is such that the ring D and the washer 3 are compressed to a slight extent against the shoulder J. During the opera tion of the cams 11, therefore, any further downward movement of the jacket C will bring the upper end of this jacket a slight distance below the washer 6, causing the ring B to very tightly lnu, the insulator B (see Fig. 8). But when the rollers 6 rest in the depressimls 12 (see Fig. l), the ring I) will then again expand a little, and this causes the upward movement of the jacket (I on the insulator, thereby reducing the space be tween the under side of the washer (J and the top of the jacket. Should the pressure in the engine tend to raise the insulator B, durint the operation of the engine, by a slight or possible further compression of the washer 3, the ring D will be lifted against the bevel con the lower end of the jacket, thus causing the rinp to again contract very tightly, so that this rim; l). which is of less internal diameter than the annular shoulder i) on the insulator, not only cooperates with the jacket and other elements to prevent the insulator from bein forced out of the plug by the pressum, but also serves to prevent leakage of the pressure.

I do not limit myself to the exact conslrnf'iitm shown and described.

What 1 claim as my invention is:

1. A spark plug comnrisinga metal socketmember adapted to be attached to the cylinder of an internal-eombusti(in-engine, an insulator adapted to enter said socket-member, a metal jacket inclosilig the outer portion oi" said insulator and adapted to enter the sorkctaiu-mbor, a bail provided With hubportions, means to pivot said hub-portions upon the opposite sides of said jacket, said sm-lt'ct-member having notches to receive said means to prevent rotation of said jacket therein, whereby the jacket is locked against rotation. lateral projections on the Socketmelnber. means carried by said hub-portions to engage said projections and thereby hold said iiisulator and jacket tightly within the sorlo-t-nu-mber when said bail is moved in one direction, and means on the insulator to engagithe opposite ends of the jacket, so that said jacket forms a bottomless receptacle i 'acket is locked a ainst rotation lateral roections on the socket-member, means carried by said hub-portions to engage said proections and thereby hold said insulator and jacket tightly within the socket-member when said bail is moved in one direction, and means to removably secure said jacket on said insulator, said bail having a lever handle for the operation thereof and by which to liftv said jacket and insulator out of the sockctanember.

3. A spark plug comprising'a metal socket-- member adapted to be attached to the cylindcr of an internal-connbustionengine. an in sulator adapted to enter said socketanember a metal jacket inclosing the outer portion 0 said insulator and adapted to enter the socketancmber, a bail provided with hubportions, moms to pivot said hub-portions upon the opposite sides of said jacket, said jacket. having lateral proje 'tions to engage said socket-member and pre 'ent rotation of the jacket therein, whereby the jacket is locked against rotation, lateral projections on the socketanember, means carried by said hub-portions to engage said projections and thereby hold said insulator and jackettightly within the sm'lwlanember when said bail is moved in one direction. and means to secure said jacket on said insulator, so that said jacket is remlered removable from the socketmember by a single movement of said bail.

4. A spark plug comprising a mrtal socket-niember adapted to be attached to the cylimlcr of an internal-combnstioIH-ngine, an insulator adapted to enter said socketmember, a metal acket having a beveled inner end inclosing' the outer portion of said insulator and adapted to enter the socketmember. a bail provided with hubmrtions, means to pivot said hub-portions upon the opposite sides of said jacket, lateral project1ons on the socket-niember, means carried by said hub-portions to engage said projections and thereby hold said insulator and jacket tightly within the socket-member when said bail is moved in one direction, and devices on the insulator to engage the opposite ends of the jacket, so that said jacket forms a bottomless receptacle for said insulator, and whereby said bail forms a swinging handle for said receptacle, one of said devices comprising a resilient split beveled ring forming a cushion for the inner end of said jacket, said socket-member having a shoulder to support said ring, whereby the ring is contracted by the operation of said ball.

5. A spark plug comprising a metal socket-member adapted to be attached to the cylinder of an internal-combustion-engine, an insulator adapted to enter said socketmember, a metal jacket inclosing the outer portion of said insulator and adapted to enter the socket-member, a'bail provided with hub-portions, means to pivot said hub-portions upon the opposite sides of said jacket, lateral projections on the socket-member, means carried by said hub-portions to engage said projections and thereby hold said insulator and jacket tightly; within the socket-member when said had is moved in one direction, and devices to removably sccure said jacket on said insulator, said bail having a lever handle for the operation thereof and by which to lift said jacket and insulator out of the socket-member, one of said devices comprising a resilient cushion for the inner end of said jacket and said socket-member having a shoulder to support said cushion.

6. A spark plug comprising a metal socket-member adapted to be attached to the cylinder of an internal-combustioil-engine, an insulator adapted to enter said socketmember, a metal jacket having a beveled wire end and inclosing the outer portion of said insulator and adapted to enter the sockct-member, a bail provided with hubportions, means to pivot said hub-portions upon the opposite sides of said jacket, latcral projections on the socket-member, means carried by said hub-portions to engage said projections and thereby hold said insulator and jacket tightly within the socket-member when said bail 1s moved in one direction, and devices to secure said jacket on said insulator, so that said jacket is rendered removable from the socket-member by a single movement of said bail, one of said devices comprising a soft washer and a split beveled steel ring which forms a gas-tight cushion for the inner end of said jacket, and said socket member having a shoulder to support said cushion, whereby the ring is contracted by the operation of said bail.

7. A spark plug comprising a metal socket-member adapted to be attached to the cylinder of an internal-combustion-engine, an insulator adapted to enter said socketmember, a metal jacket inclosing the outer portion of said insulator and adapted to enter the socket-member, a bail provided with hub-portions, means to pivot said hub-portions upon the opposite sides of said jacket, lateral projections on the socket-member, means carried by said hub-portions to engage said projections and thereby hold said insulator and jacket tightly within the socket-member when said bail is moved in one direction, having provisions to permit slight outward movement of said jacket after said bail is fully adjusted, and devices on the insulator to engage the opposite ends of the jacket, thereby to hold the insulator against displacement from the jacket, and so that said jacket forms a bottomless rcceptacle for said insulator, and whereby said bail forms a swinging handle for said receptacle, one of said devices comprising a resilient cushion to produce said outward movement of the jacket, and said socketmember having a shoulder to support said cushion.

S. A spark plug comprising a metal socket-member adapted to be attached to thecylinder of an internal-combustion-engine, an insulator adapted to enter said socketmember, a metal jacket inclosing the onlcr portion of said insulator and adapted to onfor the socket-member, a 'f provided with hub-portions, means to jlltwt said hub-por tions upon the opposite les of said jacket, lateral projcctionson the socket-member, means carried by said hub'portions to engage said projections and thereby hold said insulator and jacket tightly Within the socket-member when said had is'moved in one direction, having depressions on the hubs to permit slight outward movement of said jacket after the bail is fully adjusted, and devices to removably secure said jacket on said insulator, said bail havi g a lever handle for the operation thereo" and by which to lift said jacket and insulator out of the socket-member, one of -:,aid devices comprising a resilient cushion to-produce said outward movement of the jacket, and said socket-1nember having a shoulder to support said cushion. 9. A spark plug compriding a metal socket-member adapted to be attached to the cylinder of an internal-combustion-engine, an insulator adapted to enter sarid socket-member, a metal jacket inclosing the outer portion of said insulator and adapted to enter the socket-member, a bail provided with hub-portions, means to pivot said hubportions upon the opposite sides of said acket, lateral projectlons on the socket nlcmber, means carried by said hub-portions to engage said projections and thereby hold said insulator and jacket tightly within the socket-member when said bail is moved in one direction, having rollers on said lateral projections, with seats on said hubs to receive said rollers and permit slight outward movement of said 'acket after said bail is fully adjusted, an devices'to secure said jacket on said insulator, so that said jacket is rcndercdrcmovable from the socket1nember by a single movement of said bail, one

ammo

of said devices comprisin a resilient cushion to roduce said outwar movement of the jac et.

10. A spark lug comprising a metal socket-member a apted to be attached to the cylinder of an internal-combustion-engino, an insulator adapted to enter. said socketmember, a metal jacket inclosing the outer portion of said insulator, adapted to enter the socket-member, a metal s ring encircling the insulator and engaging t e inner end of said jacket, said insulator and socket-member having shoulders to form a seat for said spring, so that said spring and jacket are carried by said insulator and are removable 'from the outer end thereof, and means for forcing the jacket inward to compress said spring.

11. The said spark plug, as set forth in claim 10, in which said sprin consists of a split metal ring, said jac et iaving a bevel to engage and thereby contract the ring when the jacket is forced inward. 1

12. The said spark plug, as set forth in claim 10, in which said sgiring is provided with means to form a stu ng box or gland to prevent leakage of the engine pressure.

13. In a spark plug, the combination of a socket-member adapted for attachment to an internal combustion engine; an insulator for insertion in said socket-member, means carried by said insulator to produce the spark for c'ausin i nition in said engine, devices to..force t e insulator inward and hold it in lace in said socket-member, and means inc uding a metal spring to yieldinFly resist the inward movement of said insu ator and to prevent leakage of ressure from the engine, said devices inc uding a sleeve held against rotation during the operation thereof to compress the spring, and said spring providing a resilient metal cushion.

14. A structure as specified in claim.l3,

in which said siring 1s in the form ofa metal ring whic is split to contract upon the insulator when the insulator is forced inward, which ring is beveled, and means to engage the bevel of the ring to produce said contraction thereof.

15. A structure as s ecified in claim 13, in which said spring is (irectly subject to the action of said devices, so that the ressure exerted by said devices against said spring is not communicated thereto through said insulator.

Signed by me at Chicago, Illinois, this 26th day of March, 1917.

MORTON G. BUNNELL. 

